Chuck.



`tional View o't' a UNITED STATES PATENT OFFICE.

VERNR JaWAHLSTROM, OF BROOKLYN, NEWYORK, ASSIGNOR OF ONE-II-IALF TOBERNHARD T. BURCHARDI, OF BROOKLYN, NEW YORK.

CHUCK.

Application filed October 14, 1910. Serial No. 586,989.

To all whom it may concern.'

Be it known that I, VERNER- J. WAHL- s'raoir, a citizen of the UnitedStates, residing at Brooklyn, County oi' Kings, and State of New York,have invented a new and use'- ful Improvement in Chucks, of which thefollowing is a specication.

This invention relates to in chucks, and it has for' its main objectsthe production of a device of this general character of increasedcapacity and etticiency.

Vith these and other objects not specifically mentioned in view, theinvention consists in certain constructions and combinations which willbe hereinafter fully described and then specifically pointed out in theclaims hereunto appended.

In 'the accompanying drawings which orm a part. of this specificationand in which like characters of reference indicate the same parts,Figure l is a central secdevice constructed in accordance with theinvention, Fig. 2 is a sectional view taken on the line 2-2 in Fig. 1,Figs. 3 and 4 are sectional views taken on the line 3 3 in Fig. l,showing they jaws in diit'erent positions, Figs. 5 and G are plan viewsoi one of the jaws showing the parts in diiferent positions, Fig. 7 is asectional view taken on the line 7-7 in Fig. 5, and Fig. S is an endelevation of the jaw shown in Figs. 5, 6 and 7. i

In the device selected to illustrate the invention, there is provided abody 9 havii'ig three radial 4'slots 10 cutI through its wall to acentral aperture 11 adapted to receive a tool shank. The body is furtherprovided with a shank 12, driven or otherwise fastened in the body forthe purpose of attaching the device to adrill press or other machinetool. The device is further provided with an annular shell 13surrounding the body and rotatable thereon. This shell is providedwithlthree internal cam faces 14, and is held in position by means oftwo caps 15, 16 screwed to the shell and engaging rabbets 17, 18 formedon the body 9. yA spring 19 is coiled around the body within the shell,one end being fast to the body and the other to the shell, as indicatedin Fig. 1.

That portion of the device so far described is old and well known in theart, and a more detailed description of its construction is deemedunnecessary to a full understandan improvementing of the presentinvention, and is therefore omitted in the interest of brevity.

For the purpose of clamping a tool shank in the aperture 9, there isprovided a jaw, or a plurality of jaws, working in the slot 10. Thisjaw,or these aws, may vary within wide limits. As shown, however, what maybe termed rocking jaws are employed. Each of these jaws, marked 20, isprovided at its outer end with a hook 21 which is in engagement with aledge 22 formed in one wall of each of the slots 10. By reference toFigs.` 3 and 4, it wllbe readily understood that the hooked. end of thejaws are wider than the slots in which the jaws Awork, and that theledge 22 lies in a vplane which does not intersect the axis of the body9. When the shell 13 is rotated by the spring 19, the internal cam faces14 slide by the outer end of the jaws 2O and tend to force them inwardtoward the axis of the chuck. The hooked end 21 of the jaws in Contactwith the ledge 22 prevents one side of the jaws from traveling inward asfast as the other.4 The et'ective result of this is a rockingmovementfof the jaw which serves to translate a small movement,initially set up by the internal canrfaces, into a relatively largen'nivement of the jaws toward the axis of the chuck. This can be bestunderstood by an inspection of Figs. 3 and 4. In Fig. 3, the'jaws areshown in wide open position. In Fig. 4, they are shown in theirinnermost position. It will be readily understoodthat they can onlyreach the latter position by heilig rocked a1id-1noved inward by therocking movement. l

Vhile in certain constructions, the jaws alone might be relied upon toclamp thetool shank by direct contact; in the best constructions and asshown, a tool gripper carried by the jaw is en'iployed. This gripper,marked 2G, is a segmental rocking gripper and is seated in a recess 23formed on the inner end of the jaw 20, as clearly shown in Figs. 3 and4.. It is provided with lingers' 27 which interlock with fingers 2S onthe .jaw 20. The bearing face 29of eac-h gripper is cam shaped so thatthe grippers are, by contactA with a tool shank, caused to tightly clampa tool shank in the aperture 11 in a well known manner. The upper andlower ends' of the jaws are provided with segmental channels 30concentric with Patented July 4, 1911.

t ployed. One end 'of this spring is secured Figs. 5 and in the jaw andthe other in the gripper,

,IVhen a. plurality of jaws and grippers are employed, each gripper isprovided with an upwardly projecting stud 34 which engages oneof the4slots 35 cut in the lower face of a plate 36 centrally located in theupper part of the aperture 11.

lhe mechanism just described serves' to control the rocking movement ofthe several gripper/s and insure uniform movement of the same so that atool shank will always be Ycentrally clamped in the aperture.

In view of the foregoing,'a detailed description of the 'operation ofthe device is -*eemed unnecessary and is therefore omitt d in theinterest of brevity.

Y Changes and variations may be made in the structure by means of whichthe inventionis carried into effect. The invention, therefore,l isnot tobe restricted to the precise details of the structure shown anddescribed.

IVhat'iis claimed is:

l. In a chuck, the combination with a body -having a slot, of an annularshell surroundingtlie body and having an internal cam face, a aw mountedand shaped to turn `within the slot the outer end of said jaw lying inthe path of the cam face, and means for limiting the movement of oneside of the jaw/to cause it to turn within the slot'. y v2. I nfa chuck,the combination with a body 'having a slot., of an annular shell sur--rounding the bodyand having an internal. cairrface, a )aw mounted andshaped toygturnI withinv the slot and 'having at its outer end a hookwider than'thc slot and lying in the path of the cam face,;and means inthe path of the hook to limit its movementwhereby i the jaw is caused toturn in the slot.

In a chuck, the combinationwith a body'liaif'ingia slot, of an annularshell sur- `rounding the body and having an internal cam face, a jawmounted and shaped to turn within the slot and having at'its outer endan integral hook wider thang the slot and llying in the path'of the camface, and means in the path of the hook to limit its .movement wherebythe jaw is caused tof burnin the slot.

4. In a chuck, the combination with a body having a slot, of an annularshell surrounding tlie body and having an internal cam face, a jawmounted and shaped to turn within the slotand having at its outer end anintegral hook wider than the slot and lying in the path of the cam face,and means at one side of the slotand in the rounding rthe bodyand-having an internal y ath of4 the hook to limit the movementfof t iehokvcam face, a jaw mounted andi shaped to turn wtliin the slot andhavino at its outer end an integral hook wider tIian the slot and lyingin the pat-h of the cam face, and a ledge at one side of the slot andin. the path of the hook to limit the movementl of the hook whereby thejaw is caused to turn in4 having an internal cam face, a jaw working inthe slot and having atits outer end a hook widerthan the slot/ and lyinginthe path of the cam face /witli its end in engagement with theledgefa/rl otally carried by the jw;r

7..In a chuck, tli @combination witlia' body having a 1-ad"/il/slotprovided a one side with a ledge wider than the slot and lying in aplane tha/t does not intersect `the a-tool gripper pivaxis ofthe body,o/tan annular shell surrounding the body and having an internal cani'face, a Jaw working inthe slot andhaving at its outer end a hookwider/thun the slot' and lying in tl'ie path/fof the cam face l with'its end in engagement 'with the ledge,

and a tool gripper/Pivotally carriedby'the hei'eoffI have signed mynaine tt'itliLi/s'specification in thel presence of two subsril'iingwitnesses.

. Witnesses: o

